Genetically Diverse Severe Fever with Thrombocytopenia Syndrome Virus Circulates in Shelter and Companion Dogs in South Korea

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne zoonotic pathogen that continues to cause a substantial public health burden in South Korea, yet the molecular epidemiology of SFTSV in dogs, particularly shelter populations, remains poorly characterized. To address this gap, blood samples from 715 dogs, including companion and shelter animals, were collected nationwide in 2024 and screened for SFTSV using RT-PCR targeting the S, M, and L genomic segments, followed by sequencing, phylogenetic analysis, and virus isolation. SFTSV was detected in 16 dogs (2.2%), with significantly higher prevalence in autumn, in the southern region, in shelter dogs, and in younger animals. A localized cluster of six infected dogs was identified in a southern shelter during autumn, and phylogenetic analysis revealed the circulation of three genotypes (B2, D, and F). Live virus was successfully isolated from one shelter dog, and this isolate belonged to genotype F, representing the first isolation of this genotype from dogs in South Korea. These findings demonstrate that dogs are exposed to genetically diverse SFTSV strains circulating in tick populations and support the use of canine surveillance, particularly in shelters, as part of a One Health approach to monitor and mitigate the risk of SFTSV transmission.